Supervisory control-circuits for telephone systems.



SOPATERSON.

SUPERVISORY CONTROL CIRCUITS FOR TELEPHONE SYSTEMS.

APPLICATION FILED OCT. 17. 1914.

1,269,499. I Patented June 11, 1918.

Z/ Z/i 727 E55 55. [EL/5272321 EEZULZEZFEZZFEUZY UNITED sTATEs PATENTonmon.

SAMUEL PATERSON, or KENTON, MANITOBA, oANAnA, AssIGN'oI'z. r'o xntnooeSWITGHBOARD AND SUPPLY COMPANY, or CHICAGO, ILLINOIS, A .GORPORAA TIONOF ILLINOIS.

SUPERVISORY CONTROL-CIRCUITS FOR TELEPHONE SYSTEMS.

Specification of Letters Patent.

Patented. June 11, 1918.

Application filed October 17, 1914. Serial N o. 867,213.

7 object of my invention is toprovide separate clearing-out and recallsignals for the operators cord circuit, which signals may beindependently operated from a connected magneto substation. In thepreferred embodiment of my invention I. provide clearing-out ordisconnect and recall signal control relays for the cord circuit incombination with clearing-out ordisconnect and recall signals which maybe independently operated from a connected substation. For the.purposeof controlling these signals I pro- 25.

vide a well-known form of substation having a generator which may beconnected in bridge of the telephone line or have one of its terminalsgrounded and the other terminal connected to one limb of the line. Ialso preferably connect the line drop to one of the limbs of the lineand ground it so that a subscriber by grounding his hand generator bythe use of a push button can operate the line drop without giving anyindication of his call at any of the other substations connected to hisline.

The figure shows a cord circuit at a central exchange, arranged toconnect tWo magneto substations.

When lines are connected by the cord circuit the subscriber at aconnected substation by pressing his key and actuating his handgenerator as is usual forslgnaling the central operator, will actuatethe recall signal. Should the subscriber actuate his hand generatorwithout pressing'the grounding key as is usual for ring-off purposes, hewill actuate the clearing-out signal without effecting the recallsignal. In this way the opera' tor may distinguish'between aclearing-out and recall operation of the substation generator. I

Referring now in general to my invention as illustrated, it comprises awell-known form ofmagneto substation A and in addition to the usualequipment I provide a grounding key 1 having a normally closed contact 2and normally open grounded contact3. The substation A terminates at theexchange in a simple drop and jack line circuit L which comprises asignal S and jack J. The substation A is preferably located on a partyline and to this end I have shown party line taps A and A The groundingkey lat the substation is used when signaling the exchange so that whenthe hand generator at the substation A is operated, and the key 1operated to close the normally open contact 3, the central olfice iscalled secretly, or the key used to recall the operator as will be morefully described in the following specification.

A cord circuit C is provided and com prises an answering plug P and acalling plug P connected by the heavily marked conductors A and 5. Alistening key LK is shown which when operated bridges the op- 4 and 5and a ringing key RK is also shown and when operated connects theringing generator G. A disconnect relay DR is provided which controlsthe disconnect signal DS and a recall relay RC is also provided eratorstelephone 0 to the cord conductors which controls the recall signal RSwhich signal is preferably a colored lamp to distinguish from thedisconnect signal. A push button circuit breaker PB is provided which Ais preferably common to all jacks and used for effacing the recall lampwithout removing the connected plugs. A switch 4' is provided whichnormally connects ground to the cord but when thrown to its alternateposition removes ground so as to provide an ungrounded cord for certainconnections.

To the right of the drawing I have shown a magneto substation B similarto that of A and also terminating at the exchange in a line circuit Lsimilar to that of L. substation B is preferably located on a party lineand I have shown the party line taps B and B Having described in generalthe apparatus as illustrated I will now describe the operation of myinvention.

Assuming now that the subscriber at the substation A wishes to conversewith the subscriber atv the substation B, the subscriber A- removes hisreceiver and operates the grounding key 1 to close the grounded contact3 and at the same time operates the hand generator 6. The signal S atthe exchange is operated, the circuit being traced from ground throughthe generator, tip line limb, normally closed contacts of the jack J,through the winding of the drop signal 5 to ground, actuating the drop.The operator inserts the plug P into the jack J and throws her listeningkey LK to ascertain the wants of the calling sub- ;scriber. The operatorupon testing and finding the line of B idle inserts the plug P into thejack J operates the ringing key BK to connect ringing current to thecalled line. The circuit of the ringing current is traced from theungrounded pole of the generator G, closed contact of the ringing keyBK, tip contacts of the plug P and jack J through the call bell of thecalled substation, normally closed contact 2 sleeve Y contacts of thejack J and plug P to ground. The called subscriber having answered, thetwo subscribers are now in conversational circuit, the talking clrcuitbeing traced over the heavily marked conductors.

The subscribers having finished conversation they replace theirreceivers upon their respective switch-hooks. The subscriber atsubstation A having replaced his receiver operates the hand generator 6to send ourrentthrough the winding 7 of the relay DR,

the circuit being traced from the generator to the line limb, tipcontacts of the jack J and plug P, conductor 4, winding 7 conduct-or 5,sleeve contacts of the plug P and 'jack J, line limb, normal contact 2,back to the generator. The energization of the relay DR closes itsalternate contact 8 and establishes a circuit for the clearing-outsignal DS the circuit being traced from battery to normal contact 9 ofthe push button circuit breaker PB, conductor 10, third contacts of thejack J and plug P, conductor 11, through the signal DS, conductor 12,alternate contact 8, winding 13, conductor 1 1 to ground at normalcontact 15, lighting the signal DS. The subscriber at the substation Balso operates his generator sending current through winding 7. Theoperator noting the signal DS knows disconnection is desired and removesplugs P and P from the connected jacks J and J thus opening the circuitfor relay DR which dee'nergizes and eflaces the signal DS thus placingthe cord circuit C in condition for other conl ne'ctions.

Assuming as before that the two subscribers A and B have finishedconversation and that subscriber at substation A has given thedisconnect signal as before described to light the signal DS' andassuming further that the subscriber at B wishes to recall, thesubscriber at the substation B operates the grounding key as usual incalling and at the this operation of the generator establishes a circuitfor the recall relay BC traced from ground at switch 4, the winding 16of relay RC, upper half of winding 7 conductor 4, normal contact ofringing key BK, tip contacts of the plug P and jack J line limb,generator 6 to ground at alternate contact 3 of the grounding key 1 Thiscauses the energization of relay RC which closes its alternate contact15 establishing an energizing circuit for recall signal RS and lockingcircuit for RC traced from battery, normal contact?) of button PB,conductors 10, 17, third contacts of the jacks and plugs, the conductors11, 18, through the signal BS, winding 19 to ground at alternate contact15. The interruption of normal contact 15 eifaces or prevents thelighting of the disconnect signal DS and the operator noting the lightedrecall signal RS throws her listening key LK and inquires as to thewants of the party recalling. To eflace signal BC the operator actuatesswitch PB to open its normal contact 9 to deenergize the relay BC toefi'ace signal RS.

In the preferred form of my invention I use a lamp signal but it is tobe understood that my invention is not to be limited thereto. I alsocontemplate using my invention in other ways than that shown andtherefore I do not desire to be limited to the exact structure as shownand described but aim to cover all that which comes within the spiritand scope of the appended claims.

Having described my invention, what I claim as new and desire to secureby United States Letters Patent, is-

1. A telephone system comprising telephone lines, an operators linkcircuit for connecting to said lines, disconnect and recall relays forthe link circuit, and control circuits whereby said relays may beoperated selectively from a connected substation.

2. A telephone system comprising telephone lines, an operators linkcircuit having a terminal plug for connecting to said lines, disconnectand recall relays for the link circuit, and grounded and metalliccontrol circuits whereby said relays may be operated selectively from aconnected substation.

3. A telephone system comprising telephone lines, an operators linkcircuit having a terminal plug for connecting to said lines, adisconnect relay connected in bridge of the talking conductors of thelink circuit, a recall relay having one terminal of 4. A telephonesystem including subscribers telephone lines, an operators link circuitfor connecting a pair of said lines in conversational circuit, adisconnect signal and a recall signal for said link circuit, meanscontrolled over one of the connected lines for operating said disconnectsignal, and means controlled over the other of said connected lines forefi'acing said disconnect signal and for operating the said recallsignal.

5. A telephone system including a subscribers telephone line, substationapparatus connected thereto provided with a switch hook, a link circuitfor connection to said telephone line, a disconnect signal and a recallsignal for said link circuit, and means independent of said switch hookcontrolled from the said substation for selectively operating saidsignals.

6. A telephone system comprising subscribers telephone lines, anoperators link circuit for connecting said lines in conversationalcircuit, disconnect and recall relays individual to the said linkcircuit, and means controlled by a connected one of said subscribers forselectively operating said relays.

7. In a telephone system the combination with a plug ended link circuitconnected to a subscribers telephone line, of a disconnect and a recallsignal individual to said link circuit, circuit closing means forclosing a bridge across said line, means independent of said closingmeans for operating one of said signals, and means controlled from saidsubstation for subsequently operating the other of said signals, and forefi'acing the first of said signals.

8. A telephone system comprising subscribers telephone lines, anoperators link circuit for connecting said lines, disconnect and recallrelays individual to the link circuit, and means controlled by theconnected subscribers for selectively operating said relays.

9. A telephone system comprising telephone lines, an operators linkcircuit for connecting said lines, a disconnect relay and a recall relaynormally connected to a conductor of said operators link circuit, andmeans controlled from the substation of a bridging the substationreceiver across said line, a pair of signals for said link circuit, andmeans operable after said substation switch has disconnected saidreceiver from in bridge of said line to selectively operate saidsignals.

11. A telephone system comprising tele-' phone lines, an operators linkcircuit for connecting said lines, a disconnect signal and a recallsignal for said link circuit, means included in the link circuit and controllable from the substation of a connected one of said lines foroperating said signals, and means controlled from the other one of saidlines for thereafter operating the other of said signals and forefiacing the said first signal.

12. A telephone system including a calling and a called subscribersline, a link circuit for connecting said lines in conversationalcircuits, a pair of signals for said link circuits, means controlledfrom the calling substation to operate one of said signals, and meanscontrolled from the called substation for eflacing said signal and foroperating the other of said signals.

13. A telephone system including a pair of subscribers telephone lines,a link circuit for connecting said lines in conversational circuit, apair of signals for said link circuit, means controlled over one of saidlines for operating one of said signals, and means controlled over theother of said lines for efl'acing said signal and for operating theother of said signals.

Signed by me at Kenton in the District of Brandon, Province of Manitobain the Dominion of Canada, in the presence of two witnesses.

SAMUEL PATERSON.

GEo. J ONES, FRANK RoEwE.

copies of this patent may be obtained for five cents each, by addressingthe Gommissioner of Patents, Washington, D. G.

